I think they were created in different years. Could possibly make a difference to the time of day.
but if they were intended to be shown next to each other (for some kind of dramatic effect i'm guessing), then there was a continuity error, surely.
The artist does like to get its audience thinking. Originally they were not shown together naturally.
oh right, ta! anyway, it is jesus knocking at the door (i assume) so his lantern is probs significant to being a light in the world (wooo get me!)